1. Field of the Invention
The present invention relates to a driving apparatus and, in particular, to a driving apparatus that is characterized by a single endless chain and manually powered linear propulsion, mainly used for non-motorized vehicles or vessels with stable support.
2. Description of Prior Art
Vehicles and vessels need to be driven by power. Manually powered devices are commonly used in non-motorized wheel vehicles, among which some have linear reciprocating driving mechanisms for the purpose of substituting for walking rather than entertaining or exercising. Their structures are complex. Few can be put into actual use.
Chinese Pat. No. 99108216.8 (CN1275511A) discloses a bicycle with linear movement of pedaling. It has a toothed rack driving mechanism affixed on a tilted square frame. There are two toothed racks in a sliding groove. Depression of either pedal will cause the racks to move, thus draw sprocket wheels and a chain, and transfer the power to a rear driving wheel. A reset gear is used for reset control.
Other related patents are U.S. Pat. No. 6,129,646 (Farmos), U.S. Pat. No. 5,236,211 (Meguerditchian), Fr,A,2544052(MICHAUDETG), U.S. Pat. No. 4,169,609 (Zsmpedro), and U.S. Pat. No. 3,891,235 (Shelly). All the above-mentioned references disclose open technical designs that employ double endless chain mechanisms for alternate propelling. The operating process is simple. However it needs two sets of components to work alternately. The structure is very complicated and there are some difficulties in processing and installation.
Chinese Pat. No. 99123093.0 (CN1298824A) discloses a bicycle with a rocking crank. Its driving mechanism adopts two prime cranks on the left and right for pedal driving. The rear end of the crank is connected with the shaft end of a rear wheel with a driven crank linked in between, to drive a small sprocket and form a secondary transmission together with a coaxial large sprocket. Finally, the driving power is transmitted to the driving shaft of the rear wheel. Its method of operation approximates the linear movement of pedaling. But with too many transmission links, its efficiency is unavoidably reduced.
Chinese Patent Application (Application No. 01132621.2) discloses “a tractive chain-gripping cycle” including the structure of a steel wire rope traction. However, the steel wire rope will curl in the course of transmitting torque via a small pulley and the curl will affect normal operation of the cycle. In addition, the mechanism sometimes fails in reversing.
Obviously, the mechanism of the linear pedaling type shall first ensure its smooth and continuous operation, as well as the convenience during manufacture, especially avoid excessive transmission links and reduce idle runs so as to improve transmission efficiency.